I think what you have is the classic example of a “late bloomer”. I don’t weight training in and of itself mattered as much as his applying high intensity training at a time when his hormone production was at its highest point in his life to go along with a growth spurt. If he had well rounded motor abilities and was running 11.7ish as someone who was not near the end of physical maturity then entirely plausible and not out of the question. However, if he was already physically mature then it’s entirely suspect.
